Clutch transmissions can be used in gas turbine engine systems. Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. Gas turbine engines typically include one or more compressors, a combustor, and one or more turbines. In typical aerospace applications, a fan or propeller is used to provide the majority of the engine thrust and is located in front of the core engine. The compressor includes alternating stages of rotating blades and static vanes, which increase the pressure of the air as it travels through the gas turbine core. The compressor thus outputs higher-pressure air, which it delivers to the combustor. A fuel pump supplies pressurized fuel (such as kerosene) to the combustor, typically via one or more fuel injectors. In the combustor, the fuel is mixed with the higher-pressure air and is ignited by an igniter. The products of the combustion reaction that occurs in the combustor (e.g., hot gas) are directed into a turbine. The turbine is typically made up of an assembly of discs with blades, which are attached to turbine shafts, nozzle guide vanes, casings, and other structures. The turbine converts the thermal energy supplied by the combustion products into kinetic energy. The work extracted from the combustion products by the turbine may be used to drive the fan, the compressor, and, sometimes, an output shaft. Leftover products of the combustion are exhausted out of the engine and can provide some thrust in some configurations.
Aerospace applications of gas turbine engines include turboshaft, turboprop, and turbofan engines. In typical aerospace applications, the gas turbine engine provides thrust to propel the aircraft, and also supplies power for engine accessories and aircraft accessories. Typical engine accessories include an engine control unit, a starter, fuel pumps, oil pumps, etc. Typical aircraft accessories include hydraulic pumps and electric generators to supply hydraulic and electrical power to the aircraft systems.
In some aerospace applications, the turbine engine powers a lift fan, which is capable of generating thrust sufficient to produce the forward vertical lift of the aircraft during takeoff. The lift fan may be part of a lift system that also includes a jet pipe and roll posts. The jet pipe is capable of redirecting the main engine thrust downward to provide rear vertical lift. The roll posts are mounted in the wings of the aircraft, and are used to achieve aircraft roll control. A clutch, such as a high-speed dry clutch, selectively connects the lift fan shaft to the turbine engine shaft, usually at the direction of the aircraft operator.